The present invention relates to plasma display devices.
A plasma display device is comprised of a body of ionizable gas sealed within a nonconductive, usually transparent, envelope. Alphanumerics, pictures and other graphical data are displayed by controllably initiating and quenching glow discharges at selected locations within the display gas. This is accomplished by establishing electric fields within the gas via appropriately arranged electrodes, or conductors.
The present invention more particularly relates to so-called ac plasma panels in which the electrodes are insulated from the display gas. There are two basic types of ac plasma panels, twin substrate and single substrate. The former have electrodes embedded within dielectric layers disposed on two opposing nonconductive surfaces, such as glass plates. Most commonly, the electrodes are arranged in rows on one plate and columns orthogonal thereto on the other. The overlappings, or crosspoints, of the row and column electrodes define a matrix of display sites, or cells. Each display site can be individually switched between ON (energized, light emitting) and OFF (de-energized non-light emitting) states in response to voltages applied between its electrode pair. Other twin substrate electrode arrangements, e.g., multiple segment characters, are possible.
Single substrate ac plasma panels, by contrast, have all electrodes disposed on a single one of the surfaces. The electrodes may, for example, be located at different levels within the dielectric layer disposed on that one surface. Glow discharges are then initiated in response to fringing fields appearing in the gas in the general region of overlapping insulated electrode pairs. Alternatively, electrodes of various geometries may be positioned at a single level, or plane, within the dielectric. With this "planar" geometry, discharges occur in response to fields appearing in the gas in the general region of neighboring pairs of electrodes.